Pesticide poisoning oximes

Buckley, N.A., Eddleston, M., Szinicz, L. (2005). Oximes for acute organophosphate pesticide poisoning. Cochrane Database Syst. Rev. 1 CD005085... 

Eyer, P. (2003). The role of oximes in the management of organophosphorus pesticide poisoning. Toxicol. Rev. 22 165-90. 

Kusic et al. (1991) have tested the oxime HI-6 in OP pesticide poisoning in 60 patients. HI-6 was administered four times a day as a single i.m. injection of 500 mg with atropine and diazepam treatment. Oxime therapy was started on admission and continued for 2 to 7 days. Most patients were treated with HI-6 and nine patients severely poisoned with quinalphos were treated 2-PAM Cl (1,000 mg four times per day). HI-6 rapidly reactivated human red blood cell AChE inhibited by diethoxy OPs (phorate, pyr-idaphenthion, quinalphos) as well as that inhibited by dichlorvos (a dimethoxy OP). AChE inhibited with other dimethoxy OPs (dimethoate and phosphamidon) was reported to be resistant to HI-6 treatment, whereas reactivation with malathion was slow (reactivation half-time 10 h). Both HI-6 and 2-PAM successfully reactivated AChE in quinalphos-poisoned patients, with HI-6 acting as a faster AChE reactivator than 2-PAM. 

Balali-Mood, M., Shariat, M. (1998). Treatment of organophos-phate poisoning. Experience of nerve agents and acute pesticide poisoning on the effects of oximes. J. Physiol. (Paris) 92 375-8. 

Probably the most discussed factor is the possibility of a broad-spectrum reactivator. Every new oxime could be tested for its broad-spectrum potency. However, the probability of finding such an oxime is low. Alternately, we can use a combination of two oximes. Such an approach was already applied in the former Yugoslavia (Kovacevic et al, 1989a, b) two decades ago. Candidates for this approach should be oxime HI-6 and various other oximes which are applicable in the case of tabun and pesticide poisoning. 

TABLE 2. Oximes That Have Been Used in Human OP Pesticide Poisoning... 

Eddleston M et al Oximes in acute organophosphorus pesticide poisoning a systematic review of ciinicai triais. QJM 2002 95(5) 275-283. [PMiD 11978898] (Critical review of the literature calling for a prospective randomized clinical trial of pralidoxime at WHO-recomrrrended doses [30-mg/kg bolus followed by at least 8-mg/kg/h infusion]). 

Buckley, N.A., Eddleston, M., Szinicz, L., 2005. Oximes for acute organophosphate pesticide poisoning. Cochrane Database Syst. Rev. 1, CD005085. Chigusa, H., 1995. The Tokyo subway sarin attack. In Ukai, T, Takahasshi, Y., Aono, M (Eds.), Disaster Medicine Learned from the Cases Nanko-do, Tokyo, pp. 98-102. 

Oximes Oximes are compounds capable of reactivating, in some cases the complex formed by the OP compounds and acetylcholinesterase. Chemically, oximes are mono or bispyridinium compounds which can bind to the OP-AChE complex and cause the nerve agent molecule to separate from the enzyme. Importantly, oximes can reverse the actions of OP at both muscarinic and nicotinic receptors. Thus, unlike atropine, they act at the neuromuscular junction and can thus reduce the degree of paralysis. They have been shown to be effective in the management of OP pesticide poisoning. However, their effectiveness against nerve... 

Pralidoxime (2-PAM) Pralidoxime is a commonly used oxime and is rccom-mended for all cases of moderate-to-severe nerve agent poisoning. The optimal dosage is dependent on the nerve agent, time since exposure and the cholinesterase activity of the victim, i here has been considerable experience with pralidoxime and other oximes over many years in the treatment of OP pesticide poisoning. 

The presentation and initial treatment of the characteristic acute cholinergic syndrome following severe OP exposure was considered in earlier chapters. Experience with OP pesticide poisoning has shown that in most cases, the signs and symptoms resolve after about 18 h with continuing anticholinergic and oxime treatment. Ventilation, if it had been required, can be discontinued at this stage. 

As discussed earlier, nuclear accidents liave not been die only accidents to occur in recent times. Other disasters at chemical plants have been responsible for a much greater loss of life. Tlie worst disaster in the recent history of the chemical industry occurred in Bhopal, in central India, on December 3, 1984. A leak of methyl isocyanate (MIC) from a chemical pkint, where it was used as an intermediate in the manufacture of a pesticide, spread into tlie adjacent city and caused the poisoning dcatli of more tlian 2500 people apja-oximately 20,000 others were injured. 

VI. EFFICACY OF PYRIDINIUM OXIMES IN POISONING WITH OP PESTICIDES... 

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